Let's stop calling Class D amplifiers "efficient" when they are not.

[Ken1951]

Does anyone here really only have one amp?

Two systems in the house. One with AVR only, one with AVR + Adcom GFA-555 (30+ years old). No plans for more.

 

[levimax]

You already have some SS designs where this or that transistor isn't available. You can probably do a work around for most, but not for all. Hitcahi Power MOSFETs come to mind. Popular for a minute, but I don't think you can get anything that is a drop in replacement if you need it.

At this risk of going off topic you can use Exicon ECX10N20 and ECX10P20 (available from Profusion PLC in the UK) to replace Hitachi 2SK1058 (N-Channel) and 2SJ162 (P-Channel). This information from Elliot Sound Products web page and I can verify I have built his P101 Amp with the Exicon parts and they work fine.

 

[Chr1]

At this risk of going off topic you can use Exicon ECX10N20 and ECX10P20 (available from Profusion PLC in the UK) to replace Hitachi 2SK1058 (N-Channel) and 2SJ162 (P-Channel). This information from Elliot Sound Products web page and I can verify I have built his P101 Amp with the Exicon parts and they work fine.

Thanks.
Nice one.
Duly noted and much appreciated!

 

[oldsysop]

Class D sucks !
Anyone buys a module, puts their name on it and thinks they are an amplifier manufacturer.

 

[fpitas]

Class D sucks !
Anyone buys a module, puts their name on it and thinks they are an amplifier manufacturer.

Yeah, that Putzeys guy is an idiot!

/We are joking, right?

 

[Chr1]

Think he's serious.

(Or a tad misguided and/or angry.)

 

[Chr1]

I have an LD Systems class H pro audio power amp that puts out 1500w x2 @2 Ohms. 25kg,

For if I ever need to "blow the doors off". Or have huge passive subs.
Will check the idle draw.

 

[fpitas]

Think he's serious.

(Or a tad misguided and/or angry.)
Could be drugs.

Or he never went to eBay and saw the hundreds of class AB modules for sale.

 

[Chr1]

Buys them on Ebay, as you say, then puts his name on them.
Sansui...
Aye, highly suspicious if you ask me.

 

[Sokel]

Well the ICEpower units were sensitive to the load of the speaker with audibly varying response in the upper end. The others either have it reduced to a low enough level or in the case of Purifi it appears not to be an issue. Tripath units were worse about this than ICEpower.

If we're about testing ices',mine are of the new ones, load independent,etc and if they pass my time (and brutal harassment ) test at least for their warranty period (5 years) then their good for war

(no mercy for electronics,it's people than need pampering)

 

[Chr1]

Honestly... the only abuse I give my electronics that I am aware of is when I put her music on.
My opinion. So could be biased.
Or Rick Astley.

 

[mhardy6647]

Well... the proliferation of relatively good and relatively cheap amplifier modules (generally Class D nowadays) does -- perhaps -- cause the value proposition of brands like McIntosh sidle a bit towards the nonlinear (so to speak).

(^^^ from ASR, of course)

 

[vicenzo_del_paris]

Class D sucks !

So funny !
Looking at your posts history: popping in random discussions only for posting one shot similar short psychedelic posts and then disappearing.... what an objective and well constructed argumentation!
Can you develop?

 

[Rick Sykora]

Well... the proliferation of relatively good and relatively cheap amplifier modules (generally Class D nowadays) does -- perhaps -- cause the value proposition of brands like McIntosh sidle a bit towards the nonlinear (so to speak).

(^^^ from ASR, of course)

but it is digital with VU meters AND has heat sinks too. Maybe would buy one at about half the price.

 

[mhardy6647]

but it is digital with VU meters AND has heat sinks too. Maybe would buy one at about half the price.

They look like analog heat sinks to me.
I am just sayin'...

 

[Silly Valley]

Restorer-John or others familiar with Hypex board layout and failure points,

Would a dual mono Hypex NC250mp installed in a more traditional sized case reduce heat density enough to improve longevity? Reasoning being total power draw is spread across 2 boards. And maybe just as importantly, you have only one channel idle loss per board. Not sure if this helps the output filter heat issue and adjacent component heat. Granted the single mono 250 boards are slightly smaller that the 252's but not greatly so.

Thinking something like this: https://www.audiophonics.fr/en/powe...tereo-ncore-nc250mp-2x250w-4-ohm-p-13545.html

Otherwise, the option is a Purifi in a similar case but I don't need the power of even the smaller Purifi and it is approaching twice the price. I am sure the Purifi is technically better and due to better idle heat may still have the edge for reliability. I guess the real question is, will the setup mentioned above in a meaningful way mitigate the 252 series weak points or is it better to just bite the bullet and go all in for the Purifi even though any performance gains are not likely to be audible unless of course the Hypex 250 fails.

 

[levimax]

Restorer-John or others familiar with Hypex board layout and failure points,

Would a dual mono Hypex NC250mp installed in a more traditional sized case reduce heat density enough to improve longevity?

My reading of @restorer-john post is that some components in the PS of the Hypex modules run hot and since these components are not going to be on a heat sink I don't think it makes a big difference about the case. You have information about potential issues from an insider which you would never get without ASR. The Purfi modules are most likely going to last longer and use less energy without any audible benefit unless you need the extra power. As to whether it is worth it or not that comes down to a personal utility choice with the determining factor being how much you need the money for other things valuable in your life as compared to the value of piece of mind that the Purfi modules are worth to you. No right or wrong answer.

 

[Palladium]

I'm sure I'm not a real music consumer because I never use beyond the idle 4W of my TPA3255 amps (including the Fosi's 32V PSU).

 

[NTK]

Restorer-John or others familiar with Hypex board layout and failure points,

Would a dual mono Hypex NC250mp installed in a more traditional sized case reduce heat density enough to improve longevity? Reasoning being total power draw is spread across 2 boards. And maybe just as importantly, you have only one channel idle loss per board. Not sure if this helps the output filter heat issue and adjacent component heat. Granted the single mono 250 boards are slightly smaller that the 252's but not greatly so.

Thinking something like this: https://www.audiophonics.fr/en/powe...tereo-ncore-nc250mp-2x250w-4-ohm-p-13545.html

Otherwise, the option is a Purifi in a similar case but I don't need the power of even the smaller Purifi and it is approaching twice the price. I am sure the Purifi is technically better and due to better idle heat may still have the edge for reliability. I guess the real question is, will the setup mentioned above in a meaningful way mitigate the 252 series weak points or is it better to just bite the bullet and go all in for the Purifi even though any performance gains are not likely to be audible unless of course the Hypex 250 fails.

The total idle power of the NC250MC is 7.5 W (power supply) + 3.5 W (amplifier section) = 11 W. For the NC252MP it is 8.5 W + 2 x 3.5 W (for stereo) = 15.5 W, which is 41% higher than the NC250MP. So, if everything else is the same, the NC252MP will result in roughly ~41% higher ΔTemp (= amp case temperature - ambient temperature) than the NC250MP, e.g. if the steady state temperature of a NC250MP is 10 degrees above ambient, you'd expect the NC252MP to be 14 degrees above ambient.

The Purifi 1ET400A has a 1.7 W idle loss for the amplifier section, which is 1.8 W less than NC250MC's amplifier section. If you pair the Purifi to a SMPS with the same idle loss as the Hypex, the reduction in the total idle loss is actually not very significant.

 

[Galliardist]

You want to compare full blown integrated amplifiers with active preamplifiers, micros, lighting/meters- you name it, with these bare bones module-in-a-box Class D power stages and claim a victory in the idle efficiency stakes? Come on!

OK, you want integrated figures.

My Marantz PM-10 runs at around 50W when idle - four NC500 modules with active preamplifier and lighting (no meters, but I presume they don't use that much at idle?). Voltage changes day to day here which affects the figure a little. The amp runs the tiniest bit warm over several hours' use. The Hypex modules are mounted on heatsinks, but are vertical which is the slightest worry as capacitors are at the top and may absorb some of any heat rising from lower down the board.

I regard the amp as roughly equivalent to class AB for power draw in normal use, as I don't get to turn it up very often. It is switched off when not in use. The bridged modules result in more power being drawn when idle though so it may not be a great example.

HiFI News quotes the PM12SE with one module per channel at 38W idle for comparison. The previous class AB PM-14 draws 33W when idle (I have no idea how hot that one runs and haven't heard it).

I'd suggest that in the real world idle efficiency has to be looked at on a case by case basis. You can only generalise class D as more efficient when amps are working hard.